Time management is very much important in IIT JAM. The eduncle test series for IIT JAM Mathematical Statistics helped me a lot in this portion. I am very thankful to the test series I bought from eduncle.
Nilanjan Bhowmick AIR 3, CSIR NET (Earth Science)
Eduncle Best Answer
Number of red balls in box = 40
Number of black balls in box = 60
As one ball is drawn without replacement till all balls are drawn.
∴Probability that last ball drawn is black = 60/100=3/5
Thus, option (3) is correct.